Multiboot with GRUB

by Robert L.E. BILLON

Last update2010-11-03

Foreword

GRUB is the GNU GRand Unified Bootloader. It is independant of any particular OS and may be seen as a tiny, function specific OS. It provides command line and menu driven interfaces to performs its multiboot functions.

In a few words, GRUB is : OS-neutral, interactive, powerfull

Even if you stick with LILO as as your system's primary bootloader, a GRUB boot floppy at hand is the best and fastest way to get your system back, in the case your MBR went to be corrupted.

Install GRUB on your hard disk

You can install GRUB in any partition, preferably
a partition with a stable OS and one you aren't
reinstalling all the time.

Boot as habitually on this partition.
Create in this partition a directory /boot/grub/
Copy into this directory :
- the files located in /usr/local/share/grub/i386-pc/
- your handcrafted menu.lst configuration file

Then run GRUB

grub
root (hd0,1)
setup (hd0)
quit

Voilà! A bit of GRUB (stage1) is installed
onto the MBR of your hard disk.
If one day you will remove it, then you will resort to the
classic command

Hard disks are all hd, floppy disks are fd, device numbers
starts from zero, partition numbers starts from zero and
complete device names are enclosed in parentheses.
The "slices" of the FreeBSD system are referenced with letters,
example : (hd0,1,a).